It is ordinary that a normal articulated robot is provided with only one tool. FIG. 7 is an outline view showing a general axis constitution of a handling robot of a background art. In order to arbitrarily determine a three-dimensional position and an attitude in one plane of a tool, a minimum of 4 axes of a first axis through a fourth axis are needed in this way The robot can mount a single tool at the fourth axis.
FIG. 8 is an outline view of a work working system comprising a carry in station, a work station, a carry out station, and a handling robot. An unworked work is carried in to the carry in station 1. The work station 2 works the inputted work. The carry out station 3 carries out the worked work. The tool 5 of the handing robot 4 serves to handle to deliver the work among the respective stations.
FIG. 9 is an explanatory view of an example of operation of the robot in one cycle when the single unit of the robot as shown by FIG. 7 carries a single tool in the work working system of FIG. 8. In this case, the operation is realized by, a cycle of first, {circle around (1)} the worked work 6 is taken out from the work station 2, {circle around (2)} the worked work 6 is carried out to the carry out station 3 and thereafter, {circle around (3)} an unworked work 7 is taken out from the carry in station 1, and {circle around (4)} the unworked work 7 is inputted to the work station 2.
Although it is ordinary that an articulated robot of a background art carries only one tool, when one unit of a robot is mounted with two or more of tools to control independently from each other, a working efficiency is promoted.
However, when positions and attitudes in one plane of two tools are going to be controlled respectively by one unit of the robot, 4 axes×2=8 axes are needed when a simple consideration is given thereto. However, according thereto, there poses a problem that the robot becomes enlarged and heavy and also fabrication cost is increased.